On 29.10.2018 18:54, Cherian, George wrote:
Implement workaround for ThunderX2 Errata-129 (documented in
CN99XX Known Issues" available at Cavium support site).
As per ThunderX2errata-129, USB 2 device may come up as USB 1
if a connection to a USB 1 device is followed by another connection to
a USB 2 device, the link will come up as USB 1 for the USB 2 device.
Resolution: Reset the PHY after the USB 1 device is disconnected.
The PHY reset sequence is done using private registers in XHCI register
space. After the PHY is reset we check for the PLL lock status and retry
the operation if it fails. From our tests, retrying 4 times is sufficient.
Add a new quirk flag XHCI_RESET_PLL_ON_DISCONNECT to invoke the workaround
in handle_xhci_port_status().
Signed-off-by: George Cherian <george.cherian@xxxxxxxxxx>
---
drivers/usb/host/xhci-pci.c | 5 +++++
drivers/usb/host/xhci-ring.c | 35 ++++++++++++++++++++++++++++++++++-
drivers/usb/host/xhci.h | 1 +
3 files changed, 40 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-pci.c b/drivers/usb/host/xhci-pci.c
index 51dd8e0..334c009 100644
--- a/drivers/usb/host/xhci-pci.c
+++ b/drivers/usb/host/xhci-pci.c
@@ -231,6 +231,11 @@ static void xhci_pci_quirks(struct device *dev, struct xhci_hcd *xhci)
if (pdev->vendor == PCI_VENDOR_ID_TI && pdev->device == 0x8241)
xhci->quirks |= XHCI_LIMIT_ENDPOINT_INTERVAL_7;
+ if ((pdev->vendor == PCI_VENDOR_ID_BROADCOM ||
+ pdev->vendor == PCI_VENDOR_ID_CAVIUM) &&
+ pdev->device == 0x9026)
+ xhci->quirks |= XHCI_RESET_PLL_ON_DISCONNECT;
+
if (xhci->quirks & XHCI_RESET_ON_RESUME)
xhci_dbg_trace(xhci, trace_xhci_dbg_quirks,
"QUIRK: Resetting on resume");
diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index f0a99aa..342dd5ac 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1517,6 +1517,35 @@ static void handle_device_notification(struct xhci_hcd *xhci,
usb_wakeup_notification(udev->parent, udev->portnum);
}
+/*
+ * Quirk hanlder for errata seen on Cavium ThunderX2 processor XHCI
+ * Controller.
+ * As per ThunderX2errata-129 USB 2 device may come up as USB 1
+ * If a connection to a USB 1 device is followed by another connection
+ * to a USB 2 device.
+ *
+ * Reset the PHY after the USB device is disconnected if device speed
+ * is less than HCD_USB3.
+ * Retry the reset sequence max of 4 times checking the PLL lock status.
+ *
+ */
+static void xhci_handle_tx2_wrapper_reset(struct xhci_hcd *xhci)
Maybe rename this to make it more obvious it's about a quirk.
xhci_cavium_reset_phy_quirk() maybe?
+{
+ struct usb_hcd *hcd = xhci_to_hcd(xhci);
+ u32 pll_lock_check;
+ u32 retry_count = 4;
+
+ do {
+ /* Assert PHY reset */
+ writel(0x6F, hcd->regs + 0x1048);
+ udelay(10);
+ /* De-assert the PHY reset */
+ writel(0x7F, hcd->regs + 0x1048);
+ udelay(200);
+ pll_lock_check = readl(hcd->regs + 0x1070);
+ } while (!(pll_lock_check & 0x1) && --retry_count);
+}
+
static void handle_port_status(struct xhci_hcd *xhci,
union xhci_trb *event)
{
@@ -1642,8 +1671,12 @@ static void handle_port_status(struct xhci_hcd *xhci,
goto cleanup;
}
- if (hcd->speed < HCD_USB3)
+ if (hcd->speed < HCD_USB3) {
xhci_test_and_clear_bit(xhci, port, PORT_PLC);
+ if ((portsc & PORT_CSC) && !(portsc & 0x1) &&
+ (xhci->quirks & XHCI_RESET_PLL_ON_DISCONNECT))
+ xhci_handle_tx2_wrapper_reset(xhci);
+ }
Check for the quirk first, this way I can ignore the rest of the code when
debugging other issues, and use PORT_CONNECT instead of 0x1
something like:
if ((xhci->quirks & XHCI_RESET_PLL_ON_DISCONNECT) &&
(portsc & PORT_CSC) && !(portsc & PORT_CONNECT))
Thanks
-Mathias
